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37 lines
882 B
37 lines
882 B
class CentralGravitySolver {
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constructor(body, physicsBody, options) {
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this.body = body;
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this.physicsBody = physicsBody;
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this.setOptions(options);
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}
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setOptions(options) {
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this.options = options;
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}
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solve() {
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var dx, dy, distance, node, i;
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var nodes = this.body.nodes;
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var nodeIndices = this.physicsBody.physicsNodeIndices;
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var forces = this.physicsBody.forces;
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var gravity = this.options.centralGravity;
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var gravityForce = 0;
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for (i = 0; i < nodeIndices.length; i++) {
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let nodeId = nodeIndices[i];
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node = nodes[nodeId];
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dx = -node.x;
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dy = -node.y;
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distance = Math.sqrt(dx * dx + dy * dy);
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gravityForce = (distance === 0) ? 0 : (gravity / distance);
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forces[nodeId].x = dx * gravityForce;
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forces[nodeId].y = dy * gravityForce;
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}
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}
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}
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export default CentralGravitySolver;
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